Method for positioning mobile device in wireless wide area network
First Claim
1. A method for positioning a mobile device in a wireless wide area network, wherein the method is executed by the mobile device or a server and the method comprise:
- estimating distances from the mobile device to three base stations by measuring signals between the mobile device and the three base stations;
determining three measurement circles by respectively using the coordinates of three base stations as centers of the three measurement circles and the estimated distances as the radiuses of the three measurement circles;
determining an object function, wherein the object function is expressed with a first variable, a second variable, a third variable, and a fourth variable, wherein the first variable, the second variable, and the third variable are respectively related to a specific value of a measured distance and a actual distance from the mobile device to the three base stations, and the fourth variable is a coefficient of the object function;
respectively determining a first variable coding range, a second variable coding range and a third variable coding range according to the radiuses of the three measurement circles and the distances between the three base stations;
determining a fourth variable coding range;
coding the first variable coding range, the second variable coding range, the third variable coding range, and the fourth variable coding range;
selecting a plurality of combinations of the first variable, the second variable, the third variable, and the fourth variable respectively within the first variable coding range, the second variable coding range, the third variable coding range, and the fourth variable coding range as a parent population of the object function;
performing iterations of a genetic algorithm by using the parent population as a basis to derive a best solution of the first variable, the second variable, the third variable, and the fourth variable for the object function; and
converting the best solution of the first variable, the second variable and the third variable into a position of the mobile device according to the coordinates of three base stations to position the mobile device in the wireless wide area network,wherein steps of determining the object function comprise;
determining a function f(v) according to the radiuses of the three measurement circles, coordinates of three interception points of the three measurement circles and the coordinates of three base stations; and
determining a constraint g(v) according to the radiuses of the three measurement circles and the distances between the three base stations;
wherein the first variable, the second variable, the third variable, and the fourth variable are respectively expressed with α
, β
, γ
, and λ
, while the object function is F(α
,β
,γ
,λ
)=ƒ
(v)+λ
×
g(v), and v=[α
β
γ
]T.
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Accused Products
Abstract
A method for positioning a mobile device in a wireless wide area network (WWAN) is provided. The method includes determining three measurement circles according to coordinates of three base stations and respectively calculating radiuses of the three measurement circles and distances between the three base stations. The method uses genetic algorithm to derive the best solution of a plurality of variables of an object function and estimates the position of the mobile device according to the best solution. Accordingly, non-line-of-sight (NLOS) errors are reduced, and more accurate positioning can be provided.
7 Citations
15 Claims
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1. A method for positioning a mobile device in a wireless wide area network, wherein the method is executed by the mobile device or a server and the method comprise:
-
estimating distances from the mobile device to three base stations by measuring signals between the mobile device and the three base stations; determining three measurement circles by respectively using the coordinates of three base stations as centers of the three measurement circles and the estimated distances as the radiuses of the three measurement circles; determining an object function, wherein the object function is expressed with a first variable, a second variable, a third variable, and a fourth variable, wherein the first variable, the second variable, and the third variable are respectively related to a specific value of a measured distance and a actual distance from the mobile device to the three base stations, and the fourth variable is a coefficient of the object function; respectively determining a first variable coding range, a second variable coding range and a third variable coding range according to the radiuses of the three measurement circles and the distances between the three base stations; determining a fourth variable coding range; coding the first variable coding range, the second variable coding range, the third variable coding range, and the fourth variable coding range; selecting a plurality of combinations of the first variable, the second variable, the third variable, and the fourth variable respectively within the first variable coding range, the second variable coding range, the third variable coding range, and the fourth variable coding range as a parent population of the object function; performing iterations of a genetic algorithm by using the parent population as a basis to derive a best solution of the first variable, the second variable, the third variable, and the fourth variable for the object function; and converting the best solution of the first variable, the second variable and the third variable into a position of the mobile device according to the coordinates of three base stations to position the mobile device in the wireless wide area network, wherein steps of determining the object function comprise; determining a function f(v) according to the radiuses of the three measurement circles, coordinates of three interception points of the three measurement circles and the coordinates of three base stations; and determining a constraint g(v) according to the radiuses of the three measurement circles and the distances between the three base stations; wherein the first variable, the second variable, the third variable, and the fourth variable are respectively expressed with α
, β
, γ
, and λ
, while the object function is F(α
,β
,γ
,λ
)=ƒ
(v)+λ
×
g(v), and v=[α
β
γ
]T. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for positioning a mobile device in a wireless wide area network (WWAN), wherein the method is executed by the mobile device or a server and the method comprises:
-
estimating distances from the mobile device to a plurality of base stations by measuring signals between the mobile device and the plurality of base stations; determining a plurality of measurement circles by respectively using coordinates of a plurality of base stations as centers of the measurement circles and the estimated distances as the radiuses of the measurement circles; determining an object function, wherein the object function is expressed by a plurality of variables, wherein part of the variables are related to specific values of a measured distance and a actual distance from the mobile device to the plurality of base stations, and another part of the variables is a coefficient of the object function; respectively determining a plurality of variable coding ranges according to the radius of the plurality of measurement circles and the distances between the plurality of base stations; determining another variable coding range; coding the plurality of variable coding ranges; selecting a plurality of combinations of the plurality of variables respectively within the plurality of variable coding ranges as a parent population of the object function; performing iterations of a genetic algorithm using the parent population as a basis to derive a best solution of the plurality of variables for the object function; and converting the best solution of at least a part of the variables within the plurality of variables into a position of the mobile device according to the coordinates of the plurality of base stations to position the mobile device in the wireless wide area network, wherein steps of determining the object function comprise; determining a function f(v) according to the radiuses of the measurement circles, coordinates of interception points of the measurement circles and the coordinates of base stations; and determining a constraint g(v) according to the radiuses of the measurement circles and the distances between the base stations; wherein the variables are respectively expressed with α
, β
, γ
, and λ
, while the object function is F(α
,β
,γ
,λ
)=ƒ
(v)+λ
×
g(v), and v=[α
β
γ
]T. - View Dependent Claims (11, 12, 13, 14, 15)
-
Specification